Method of neutralizing hydrocarbon oil



Patented Oct. 31, 1944 T1 isT E NT onlCE- mnmo- CARBON on,

. g I Vladimir LrChechot, Philadelphia, Pa assignor H i to The-AtlanticRefining Company, Philadel- I .1 I phi a, Pa., a corporation ofPennsylvania {No-Drawing. Application June 25, 1942,

Serial No. 448,473

Thepresent invention relates to the treatment of hydrocarbon oils, andmore particularly to improvements in the method of neutralizinghydrocarbon oils whichhave been subjected to treatment with sulphuricacid.

- It hasbeen conventional practice in the refining of hydrocarbon oils,especially viscous hydrocarbon oils, such as lubricating stocks derivedfrom parafiin distillates, to subject such oils to treatment withsulphuric acid for the removal of color'bodies and unstable compoundswhose presencev is detrimental in the finished oil- Upon completionfofthe acid treatment, the resulting acid sludge is separated fron 'the'oil, and the sour oil is neutralized'with an alkali, for exam-- ple, anaqueous solution of-sodium hydroxide. In order to prevent the formationof emulsions during, the neutralization, small amounts of rosin' soapsor similar surface tension-reducing agents have been added inconjunction with the neutralizing agent. The neutralizing operation isusually carried out at elevated temperatures in the presence of opensteam, so that the viscosity of the oil is reduced, better contactbetween the oil and the neutralizing agent is obtained, and a more rapidand complete separation of the neutralizing agent and the products ofneutralization is efiected. In many cases during the neutralization ofthe acid treated oil in the presence of rosin soaps and open steam, theneutralized oil crease in color.

I have found that acid treated oils which normally form emulsions uponneutralization, may be neutralized without emulsification and, withoutthe use of rosin soaps or similar agents, by

. acquires a rosin-like odor and an undesirable insubjecting such oilsto treatment with an aqueous not too great to permit intimate contactingwith the acid treated oil. The ratio of NaaO or K20 0 S102 in thesilicates may vary over a wide r nge, for example, from 1:1 to 1:4.Commerc lly available sodium silicate having a composition NazO.3.22SiO2may be diluted with water to the desired concentration, for example, 10

Baum, and such solution then-used in the neutralization of the treatedoil. The quantity of the silicate solution to be used depends upon theconcentration of such solution, as well as upon r 6 Claims. (01. 196-41)the acidity of the oil to be neutralized. In general, from 5 per cent to10 per cent by volume of the silicate solution, based upon the oil,hasbeen found satisfactory. In lieu of the silicate solution, per se, I mayutilize amixtur of silicate solution and alkali metal hydroxidesolution,for

example,two parts of sodium silicate and one.

part of sodium hydroxide.

My invention may be further illustrated by the following example, inwhich a comparison is made between useof. asodium silicate solution'anda sodium hydroxide-rosin ,soap solution for the neutralization of anacid treated oil.

sA lubricating oil stock having a Saybolt Universal viscosity of 300secondsat 100 Rand an A. P. I- gravity: of 24.5", derived from a dewaxedparaffin distillate, was treated with 21 pounds per barrel or.GGL'suI-phuricf acid applied in two dumps. The resulting[acidv sludgewas-settled and separated from the treated oil, and such oil was dividedinto two portions.

One portion was vigorously agitated with 6.5 per cent by volume ofsodium silicate solution obtained by diluting a Baum commercial sodiumsilicate with suflicient water to produce a 10 per cent aqueous silicatesolution. The mixture of oil and silicate solution was then steamed withopen steam, and then permitted to settle for two hours, whereupon thesilicate solution containing products of neutralization was separatedfrom the oil. No emulsification was encountered during the steamingoperation. The oil was then washed with 10 per cent by volume of Waterand dried by air blowing.

The other portion of the sour oil was vigorously agitated with 3.7 percent by volume of a 10 per cent solution of sodium hydroxide. To themixture of oil and sodium hydroxide solution was added 1 /2 per cent byvolum of rosin soap solution, and the resulting mixture was steamed withopen steam. The mixture was then permitted to settle for two hours, andthesodium hydroxide-rosin soap solution containing products ofneutralization was separated from the oil. The neutralized oil was thenwashed with 10 per cent by volume of water and dried by blowing withair.

The results of the above methods of neutraliza- Properties Silicate NaOHneut. oil neut. oil

Yield, volume per cent 9 I A. S. T. M. color 7 2% Neutralization number0. 0 5 Ash, weight per oent 0. 001 0 Oil? Conradson carbon..." 0.03 b 05Steam emulsion te t 210 542 It will be seen from the above results thatneutralization of the acid treated oil with sodium silicate solutionproduced a finished oil superior in substantlallwall respeotsstotheoilgproduced bw neutralization with sodium hydroxide rosinsoapsolution. Of particular significance is the marked r improvement incolor andsteam emulsion test of the oil produced inaocordancewith:this"invention as contrasted with the oil produced by theconventional method involving the use of sodium hydroxide-rosin soapsolution;

While the method of the present ihventioniis particularly adapted forthe neutralization of acid treated lubricating oil stockswhich-normallwtendi.

ment, which consists in intimately mixing the acid treated'oi'l withfrom 5 per-*centvtm l0iperrcent by volume ofian aqueoussolutioniofisodium silicate having a Baum gravity between 5 and 15",subjecting the resulting mixture to a steam treatv nent with open" steamand separating the neus-traiized oil'from the neutralization products.

4. The method of neutralizing hydrocarbon oil ivvl'ilcli las'beeiiisubjeoted to sulphuric acid treat- 'mjent;-Which consists inintimately mixing the acid treated oil with'an aqueous solutioncontainjingnan:v alkali-:metal silicate and an alkali metal to emulsifyunder conventional treatment;s'uclt method is also applicable to theneutralization of acid treated oilnwithaani aqueous soluti'omota: so:-.v

dium silicate; subjectingrthe resultinymixwres to a steamtreatmenizawithsopen steamzcand sepa rating'tlie neutifalizedi'oil fromthemeutmlization. products. Y v

The methomofineutrslizingi hydro'oazrhorrioilf WhiBh aeitlztreate'hydroxide, subjecting the resulting mixture to a steam treatment withopen steam, and separating theneutralized oil from the neutralizationprodllCtS*.-,-,-g a.

v Thezmethod: of neutralizing, hydrocarbon oilwhiehlhasbeen-subiectedtosulphuric acidltreatr menu; which; consistseinintimately mixing. the; acid treated oil with anaqueoussolution.contain'-' sodiumr silicate-and sodium hydroxide,..subjectingitheresultingmixturatoaasteamtreatmentwitlinopen steam andseparatinglthe neutralized oil iromlthe neutralizationproducts...

1 6: The methodof neutralizing, a sulphuriclacid;

treatedihydroca-rbon oil which normally: tends to emulsify, :upon. atreatment with. an aqueous solutionrofi sodium hydroxide, whichconsistsdmintimatelyfmixing. the :acid treated oil withanlaquw,oussolution :ofsodium silicate, subjecting the. re:- sulting mixture:to. :acsteamltreatment with, open. steam; and: separating;thexneu-tralizedl oill from; theaneutra-lizatiomproducts. v

- CHECHO'T;

